dmaengine: moxart-dma: Fix memory leak when stopping a running transfer

The vd->node is removed from the lists when the transfer started so the
vchan_get_all_descriptors() will not find it. This results memory leak.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/moxart-dma.c b/drivers/dma/moxart-dma.c
index 15cab7d..b463410 100644
--- a/drivers/dma/moxart-dma.c
+++ b/drivers/dma/moxart-dma.c
@@ -193,8 +193,10 @@
 
 	spin_lock_irqsave(&ch->vc.lock, flags);
 
-	if (ch->desc)
+	if (ch->desc) {
+		moxart_dma_desc_free(&ch->desc->vd);
 		ch->desc = NULL;
+	}
 
 	ctrl = readl(ch->base + REG_OFF_CTRL);
 	ctrl &= ~(APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN);